Air Compressor Capacity Calculation

CFM Formula:

\[ CFM = \frac{\text{Tank Volume} \times \text{Pressure Ratio}}{\text{Time}} \]

Delivered Air Flow Rate (CFM):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Air Compressor Capacity?

Air compressor capacity refers to the volume of air that a compressor can deliver, typically measured in cubic feet per minute (CFM). This calculation helps determine the actual air delivery rate of a compressor system.

2. How Does the Calculator Work?

The calculator uses the CFM formula:

\[ CFM = \frac{\text{Tank Volume} \times \text{Pressure Ratio}}{\text{Time}} \]

Where:

\( \text{Tank Volume} \) — Storage tank capacity in cubic feet (ft³)
\( \text{Pressure Ratio} \) — Ratio of discharge pressure to atmospheric pressure (unitless)
\( \text{Time} \) — Time taken to fill the tank in minutes (min)

Explanation: This formula calculates the actual delivered air flow rate by measuring how quickly the compressor can fill its storage tank to the desired pressure.

3. Importance of CFM Calculation

Details: Accurate CFM calculation is crucial for selecting the right compressor for specific applications, ensuring adequate air supply for tools and equipment, and optimizing energy efficiency.

4. Using the Calculator

Tips: Enter tank volume in cubic feet, pressure ratio (typically 2-8 for most applications), and fill time in minutes. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is pressure ratio and how is it calculated?
A: Pressure ratio = (Discharge Pressure + Atmospheric Pressure) / Atmospheric Pressure. Standard atmospheric pressure is 14.7 psi.

Q2: Why is CFM important for air tools?
A: Different air tools require specific CFM ratings to operate effectively. Insufficient CFM can cause tools to underperform or stall.

Q3: What is the difference between SCFM and CFM?
A: SCFM (Standard Cubic Feet per Minute) measures air flow at standard conditions, while CFM measures actual delivered air flow at current conditions.

Q4: How does altitude affect CFM calculations?
A: Higher altitudes have lower atmospheric pressure, which affects pressure ratio calculations and may require adjustments.

Q5: What factors can reduce actual CFM output?
A: Pressure drops in piping, air leaks, high ambient temperatures, and compressor wear can all reduce actual CFM delivery.